Violin-string-tensioning device



W. BOURKE.

VIOLIN STRING TENSIONING DEVICE- APPLICATION FILED JULY is, 1919.

1,3 1,3 0, Patented Dec. 7,1920.

' flgvzuToR ATTORNEY I UNITED STATES PATENT OFFICE.

WILLIAM BOURKE, OF NEW YORK, N. Y., ASSIGNOR 0F ONE-HALF TO LEIGH ARTHUR ELKINGTON, OF NEW YORK, N. Y.

VIOLIN-STBING-TENSIONING DEVICE.

Specification of Letters Patent.

Patented Dec. 7, 1920.

To all whom it may concern:

Be it known that 1, WILLIAM BOURKE, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Violin-String-Tensioning Devices, of which the following is a specification.

This invention relates to improvements in violin string tensioning devices.

One object of my invention is to produce a tensioning device which may be economically and quickly manufactured and which will function accurately to tension violin strings.

In a more limited aspect, the object of my invention is to eliminate the costly boring of small pivot holes and the use of a nicely fitted small pivot pin for the tensioning lever of such a string tensioning device.

With these and other objects in view the invention comprises the combination of members and arrangement of parts so combined as to co-act and cooperate with each other in the performance of the functions and the accomplishment of the results herein contemplated, and comprises in one of its adaptations the species or preferred form illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of a portion of the rear of a violin with my improved tensioning-device illustrated in place on the violin tail piece;

Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 2;

F Fig. 4 is a section on the line 4.-4 of i 2;

ig. 5 is a plan view of the base plate of a device embodying my invention before the same is assembled.

Referring now to these drawings, 1 indicates a portion of the rear end of a violin, 2 a tail-piece suitably secured thereto in one of the string slots 3 of which tail-piece is mounted a string-adjusting device 4 cmbodying my invention. Preferably, said device comprises a string-adjusting lever 10 mounted to a base plate 5 fitted beneath the front end of the tail-piece 2 and having suitable means for clamping the said base plate 5 to the tail-piece 2. As shown, the base plate 5 is so clamped to the tail-piece through the said string or key slot 3 by means of a screw 6 having, as shown, an external screw thread 7 which is screwed fast into a screw-threaded bore 8 in the base plate 5 at one end and is provided at its opposite end with a knurled nut 9 whereby the tail-piece 2 may be clamped between the base plate 5 and the said knurled nut 9 to hold the base and associated parts in place at the front end of said tail-piece 2.

The adjusting lever 10, which is substantially L-shaped in conformation, has a vertically-extending post portion 11 provided with a suitable groove 12 over which a loop 13 of the string 14 is, as shown, slipped for the purpose of securing the string 14: to the post 11. The opposite end 15 of the lever 10 extends in a horizontal direction rearwardly substantially parallel to the base plate and is moved or rocked to any desired degree for the purpose of adjusting the ten sion of the string by depressing or releasing the horizontallever. As shown, this is accomplished by means of a vertically-disposed adjusting screw 16 having a knurled nut 17 connected thereto and extending above the tail-piece 2 and having its opposite end 16 bearing against the rear end of the arm 15 of the lever 10. As illustrated, the screw 16 extends through a screw threaded bore or socket 18 located centrally in the screw 6.

In mounting levers of this character to respond accurately to the adjustment by means of the screw 16, it was heretoforefound necessary to pivot the said lever on a pivot pin in the base 5. This necessitated very careful and expensive operations and particularly the boring of very fine holes in the opposite edges of the base and through the lever 10 and the fitting therein of a very fine pivot pin. These operations are, by my invention, eliminated by mounting the lever 10 in a suitable opening or socket in the base 5 so that it will be caused by the adjusting screw to rock about a portion of the base as a fulcrum and will be effectively guided and prevented from slipping in its rocking movements, thus producing an effeotive fulcrum for permitting the accurate rocking of the lever by the action of the screw 16.

In the preferred embodiment of my invention illustrated, the base 5 is provided at its front end with a lever socket 19 and the front portion of the base 5 is preferably split as at 2021 and opened up so as to permit the assembly or entrance of a reduced portion 22 of the lever 11 to be inserted into the socket 19. After such insertion, the splits 20 and 21 are closed to confine the lever in the socket. The reduced portion 22 is preferably formed by pressing out from the metal of the lever rounded front and rear projections 23-52% at the 0pposite frontand rear edges of the lever and at the same time, the upper and lower edges 25-26 of such reduced portion 22 are similarly rounded so as to loosely rest upon the upper and lower surfaces of the base plate 5. \Vhen the tension of the string is placed upon the post 11 the lever 10 when moved by the adjusting screw 16 will turn on the front projection 23 acting as a fulcrum in contact with the front wall 27 of the socket 19, while the upper and lower rounded surfaces 2526 will by engagement with the upper and lower surfaces of the base 5 guide the lever in its rocking movement and prevent a bodily up and down movement of such lever. During this movement about the fulcrum 28 the rear projection 24 will simply ride along the wall 28 of the said socket 19. In this way I am enabled by extremely simple pressing or stamping out operations to provide means for permitting accurate rocking of the lever without boring fine pivot holes in the lever and in the base portion and inserting therein small pivot pins. I thus eliminate several expensive operations and am enabled to produce such string-tensioning devices at a materially reduced cost.

Having described my invention, I claim:

1. In a string-tensioning device, the com bination with a suitable base plate, having a socket, an L-shaped tensioning lever fulcrumed in said socket and having integral rocking means at the fulcrum of said lever, and means for adjusting said lever about said rocking means.

2. In a string-tensioning device, the combination with a suitable base plate, having a socket, an L-shaped tensioning lever provided with a reduced portion fulcrumed in said socket and having a rounded projection at its fulcrum about which the lever rocks; and means for adjusting said lever.

3. In a stringtensioning device, the combination with a suitable base plate, having a socket, an L-shaped-tensioning lever fulerumed in said socket and having a reduced portion provided with oppositely disposed rounded projections at its fulcrum; and means for adjusting said lever.

4. In a string-tensioning device, the combination with a suitable base plate, having a split socket, an L-shaped tensioning lever fulcrumed in said socket and having a re duced portion provided at its fulcrum with oppositely disposed rounded projections, and also provided with guiding projections to prevent up and down movement of the lever in relation to said socket, and means for adjusting said lever.

5. In a string-tensioning device, the combination with a suitable base plate, having a split socket, an L-shaped tensioning-lever 'fulcrumed in said socket and having a reduced port-ion provided at its fulcrum with oppositely-disposed rounded and integral projections at said fulcrum portion, and also provided with integral guiding projections whereby up and down movement of the lever in relation to said socket is prevented, and means for adjusting said lever.

In witness whereof, I have signed my name to the foregoing specification in the presence of two subscribing witnesses.

WILLIAM BOURKE.

Witnesses HELEN V. WHIDDEN, STALLO VINTON. 

